In manufacturing processes of a circuit board, after forming circuit wirings on a board, it is required to inspect the presence of a disconnection or open circuit in the circuit wirings.
Heretofore, an open circuit state in circuit wirings on a circuit board has been determined by bringing a pair of pins into contact with two different portions of each circuit wiring and then checking conduction between the positions.
However, in an area of the circuit board, such as the vicinity of an integrated circuit, where the circuit wirings are formed in close proximity to each other, it is difficult to assure a sufficient interval between the pins. On the other hand, a non-contact type inspection method (Japanese Patent Laid-Open Publication No. 09-264919) has been proposed. However, since this inspection method has still been required to bring one pin into contact with each input section of the circuit wirings, it has been suffered from complicated and time-consuming positioning operations when circuit wirings such as those around an integrated circuit are in close proximity to each other and each of the circuit wirings has a short length.
In view of the problems in the above conventional methods, it is therefore an object of the present invention to provide an apparatus and a method capable of inspecting a circuit board at a high speed.